EGR System Inspection

On other vehicles, the only way to accurately check the operation of the EGR system is to perform a systematic inspection of the entire system. The following inspection procedures are for a 95 5S-FE Camry:

• Next, with engine speed at 2500 rpm, connect the R port of the EGR modulator directly to a manifold vacuum source. The vacuum gauge should now indicate high vacuum (typically around 13") and the engine should run rough.

Note: This verifies proper high signal vacuum to the EGR valve when R port vacuum overrides the backpressure modulator.

Disconnect terminals TE1 and El at DLC1 and reattach the EGR hoses to their original location.

If the problem is related to the EGR valve itself, make sure heavy carbon deposits are not keeping the valve unseated or causing it to stick when opening. Also, if EGR valve control is OK remove the valve and check the EGR exhaust and intake passages for restrictions. Heavy carbon deposits can be removed by using a special carbon scrapping tool.

This inspection example systematically confirms the integrity of the EGR valve, VSV, backpressure modulator, system hoses, and EGR passages. Once the suspect part/component is identified, it should be individually tested and then repaired or replaced as necessary. Because slight model to model variations exist between EGR systems, refer to the Repair Manual for specific EGR system inspection procedures.

When inspecting the EGR valve, look for common problems such as unseated or sticky valves and plugged exhaust/intake passages.

Don't pay hundreds of dollars to find out what is wrong with your car. This book is dedicated to helping the do it yourself home and independent technician understand and use OBD-II technology to diagnose and repair their own vehicles.